Butterworth trained as an artist at Camberwell College of Arts and worked briefly as a tutor in drawing at Nottingham College of Art. After briefly working as a salesman, he joined the Amalgamated Press (later renamed Fleetway Publications) after submitting samples of artwork to them. Although these were turned down, he tried again, submitting a script for a sea-going adventure strip. This was accepted and Butterworth was hired as a scriptwriter, at first working primarily Western strips featuring Billy the Kid and Buffalo Bill. His interest in history (particularly naval history) led him to pen many historical comic strips for The Comet and Sun, including the Napoleonic era adventures of Max Bravo, the Happy Hussar and World War II air-ace Battler Britton.
Aside from his writing, Butterworth was a gifted editor and created a number of new papers for the firm including Playhour Pictures (soon after abbreviated to Playhour), Valentine and the teenage girls' magazine Honey.
In 1965, he became one of the main script writers for Ranger where he penned the sprawling science-fantasy The Rise and Fall of the Trigan Empire which remains one of the most popular boys' adventure strips published in the UK to this day.
Butterworth left Fleetway Publications and turned freelance.